Wash the hog plums thoroughly, cut off the stalks, chop each of them longitudinally into 2, discard the seeds, drain and keep aside. Roast the fenugreek seeds till they turn dark brown, grind into a fine powder and keep aside. Heat oil in a saucepan and add mustard. When mustard crackles, add hog plums and turmeric powder and fry. When all the moisture in the hog plums evaporates and the hog plums begin to curl up, shut off the flame. Add salt and mix well. When the ingredients cool down to room temperature, add chilli powder, powdered fenugreek, asafoetida; mix well and serve.